The prospect of a Mark Sanford primary victory in South Carolina has some Republicans complaining his candidacy will leave their party open to Democratic attack as it tries to rebrand itself among women.

On Tuesday, he took the first step in what would be an extraordinary comeback by finishing far ahead of the Republican pack in the first round of voting in the GOP primary to fill the House seat vacated by Sen. Tim Scott (R-S.C.).

A victory will match Sanford against businesswoman Elizabeth Colbert Busch (D), the sister of comedian Stephen Colbert, in a race certain to draw national attention.

Still, GOP strategist Ford O’Connell said a Sanford candidacy “could be a real nightmare” for national Republicans.

A survey from the Democratic firm Public Policy Polling last December — before the South Carolina House seat became open — showed 56 percent of women in the state held an unfavorable view of Sanford. Only 29 percent held a favorable view.

“Stephen Colbert will have a field day with this, with his sister in the race especially. Democratic strategists have to be salivating about using this as a wedge issue. A little seat in South Carolina can be a way to drive a national narrative on this wedge issue with the GOP and single women,” O’Connell said.